Production of staple fibers from continuous filaments



Feb. 4, 1941. Q w, ADDY ETAL 2,230,396

PRODUCTION OF STAPLE FIBERS FROM CONTINUOUS FILAMENTS Filed March 7, 1939 Patented Feb. 4, 1941 smear @FFECE PRODUCTHQN 0F STAPLE FmERS FROM CONTENUGUS FKLAMENTS Charles Wesley Addy and Reginald John Grinnell, Spondon, near Derby, England, assignors to Gelanese Corporation of America, a corporation of Delaware Application lidarch 7, 1939, Serial No. 260,306 Kn Great Britain April 8, 1938 1.? Claims.

This invention relates to improvements in the production of staple fibers from continuous filaments.

The continuous filaments from which staple fibers are out are invariably spun in the form of bundles containing a number (often a very large number) of filaments, and in the leading of these bundles to the cutting device there is a tendency for the filaments to be closely compacted against each other, which condition tends to persist in the shorter bundles emerging from the cutting device. Even where the filaments are cut in the dry condition, and the present invention is more particularly concerned with this 1 form of cutting, as, for example, when the filaments are led directly from a dry spinning machine or from cheeses or other packages of dry completed filaments, there is an apparent adhesion between filament and filament and consequently between fiber and fiber. The mass of fiber produced thus contains a large proportion of bundles or pencils of fibers, which makes the mass difiicult to spin into yarn. Passage through the customary opener does not readily bring about the separation of fiber from fiber necessary for good spinning, and, moreover, the action of the opener tends to break a; large number of fibers.

Drawing of the filaments from the cutting machine by an air stream as described in U. S. Patent No. 2,010,078 assists to some extent in separating the fibers, and U. S. Patent No. 2,079,094 describes a cutting arrangement in which the conduit from the cutting device proper is fitted with an air injector device serving to produce a conveying current for the fibers and to subject the fibers to a. violent air impact for the purpose of opening them. The present invention is concerned with improving the open-' ing of the cut fiber, and is particularly useful for application to cutting operations in which the fiber is drawn away from'the cutting device by an air stream as described in the two specifications mentioned above.

It has now been found that a much improved opened condition of fibers may be effected if dry filaments composed of a material prone to electrification be led on their way to' the cutting device into contact with a surface of a material that promotes electrification of the filaments by friction between the moving filaments and itself. Generally it is advantageous if the material with which the filaments contact is substantially removed in the electrostatic series from the material of the filaments. The surelectrification face may be caused to move so as continually to present a. different portion for frictional contact with the filaments. Thus, forexample, the surface may be provided in the form of a roller over which the filaments are caused to pass, the roller rotating at a peripheral speed different from the linear speed of the filaments, so that difiere-nt parts of the roller surface are presented to the moving filaments.

Whether or not a moving surface is employed, it has been found advantageous to shift the point of contact between the filaments and the surface in a-direction transverse to the direction of movement of the filaments. This may be effected, for example, by the employment of means for traversing the filaments lengthwise of the surface, or by traversing the surface itself. Again, in the case where the filaments are supplied from packages such as cheeses or cones mounted for unrolling unwinding, the traversing of the filaments lengthwise of the package during unwinding may serve to traverse them over a surface with which they contact soon after leaving the package.

Cellulose derivative filaments are particularly prone to electrification engendered by friction, and in the case of cellulose acetate filaments, for example, one or more surfaces of the following materials may be employed to produce the varnished and unvarnished woods, hard and soft rubber, phenol aldehyde resins, ebonite, fiber, glazed and unglazed porcelain, glass, hardened or case-hardened mild steel or high carbon steel, unhardened steel, black iron, enamelled iron, brass-copper, aluminium, and gutta percha. In some cases even cellulose derivative tubes or rods may be employed. v

The electrification setup in the filaments tends to separate, the filaments from each other by mutualrepulsion. This tendency'is resisted by the tension necessary to feed the filaments to the cutting device, but when thecutting of the filaments into fibers relaxes the tension, the repulsion becomes efiectiv'e to let the filaments separate, and, especially ,in conjunction with an air. stream induced, for example, by an air ejector in the delivery'pipe, produces a mass of fiber of good "open characteristics.

The delivery pipe may be -fitted with baflies to assist in opening the cut staple. Teeth may be formed on the baiiles to comb the masses of fiber passing through the pipe. Advantageously, the pipe is made of non-conducting material to reduce loss of electrification of the air-borne fibers while the opening is still proceeding, and the baffles may likewise be non-conducting. Cellulose acetate sheet is suitable for making the pipe and bailles.

The fiber discharged from the delivery pipe may be collected in boxes, bags, or in any other suitable way, and packed in a form convenient for transport to the spinning machinery.

The invention will now be described in greater detail with reference to the accompanying drawing, in which Fig. 1 is a diagrammatic elevation of one kind of fiber-cutting installation;

Fig. 2 is a plan view of a detail of Fig. 1;

Figs. 3 and 4 are sectional and end elevations respectively of a detail of Fig. 1;

Fig. 5 shows a modified cutting installation; and

Figs. 6 and 7 show alternative forms of electrifyingjdevices.

In Fig. 1, cheeses l are arranged for unwinding in a creel 2. The several ends of yarn 3 are led in zig-zag manner over fixed rods 4 and are drawn together to make a bundle 5 of suitable thickness which is, fed by rollers 6 to a cutting device I through which cut fiber is discharged by a pipe 8. Into a horizontal run 9 of the pipe compressed air is delivered by a nozzle It) so that the fibers are carried to a collectingdevice I! which may be arranged below the fioor l3.

As shown by Fig. 2, the traversing of the ends of continuous filaments I as unwinding proceeds causes the filaments to move lengthwise of the rods 4 so that the point of contact between the filaments and the rods continuously changes. The rapid movement of the filaments from the cheeses l to the cutting device I electrifies the filaments because of the friction between the filaments and the rods, the rods being composed or surfaced with suitable material for the promotion of electrification, as previously indicated.

The fibers enter the delivery pipe I in the electrified state, which is maintained by the pipes 8 and 9 being made of non-conducting material. Within the pipe 9 are bafiles l4, shown in detail in Figs. 3 and 4. Each of these consists of a conical member formed with an opening I! surrounded by teeth IS. At alternate bafiles the fibers are directed upwardly and downwardly so that any masses of fibers tend to be broken up, which action is assisted by the combing effect of the teeth ii.

The collecting device l2 comprises .an open mesh upper part II to which a bag It is secured. Entraining air escapes through the meshes of the part I! and the fibers collect in the bag ll. Fig. 5 shows the delivery pipe 9 diverted upwardly so as to deliver the fibers to a collecting device I! arranged on the same fioor as the cutting machine I.

In Fig. 6 the end of continuous filaments I9 is shown ballooning from a non-rotatable supply package 20 and passing in a zig-zag manner over electrifying rods 2| traversed across the pathof the filaments by means of the cam 22 so that fresh contact points are continually being presented to the continuous filaments.

In Fig. 7 the end of continuous filaments 23 being unwound from a cheese 24 traverses lengthwise of an electrifying roller 25, which in addition .is arranged to rotate by suitable driving means 26 to assist in the electrification oi the filaments. r

Having described our invention, what we desire to secure by Letters Patent is:

1. Process for the productionof staple fibers from continuous filaments comprising electrifying dry continuous filaments of a material prone to electrification by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction, and passing the electrified filaments to a cutting device so as to form a mass of staple fiber.

2. Process for the production of staple fibers from continuous filaments, which comprises electrifying dry continuous filaments of a material prone to electrification by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction and is substantially removed in the electrostatic series from the material of the filaments, and passing the electrified filaments to a cutting device so as to form a mass of staple fiber.

3. Process for the production of staple fibers from continuous filaments, which comprises electrifying dry continuous filaments o! a material prone to electrification by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction and is substantially removed in the electrostatic series from the material of the filaments, and passing the electrified filaments to a cutting device so as to form a mass of staple fiber, said electrifying surface being moved so as continually to present a different portion for frictional contact with the filaments.

4. Process for the production of staple fibers from continuous filaments, which comprises electrifying dry continuous filaments of a material prone to electrification by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction and is substantially removed in the'electrostatic series from the material of the filaments, the point of contact between the surface and the filaments being shifted in a direction transverse to the direction of movement of the filaments so as continually to present a different portion for frictional contact with the filaments, and passing the electrified filaments to a cutting device so as to form a mass of staple fiber.

5. Process for the production of staple fibers from continuous filaments, which comprises electrifying dry continuous filaments of a material prone to electrification by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction, passing the electrified filaments to a cutting device so as to form a mass of staple fiber, leading the fibers from the cutting device by an air-stream and combing the fibers while they are air-borne.

6. Process for the production of staple fibers from continuous filaments of cellulose acetate, which comprises electrifying dry continuous filaments of said material by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction, and passing the electrified filaments to a cutting device so. as to form a mass of staple fiber.

7. Process for the production of staple fibers from continuous filaments of cellulose acetate, which comprises electrifying dry continuous filaments of said material by-leading said filaments into contact with a surface of a material that promotes electrification of the filaments by fricstatic series from the material of the filaments, and passing the electrified filaments to a cutting device so as to form a mass of staple fiber.

8. Process for the production of staple fibers from continuous filaments of cellulose acetate, which comprises electrifying dry continuous filaments of the material by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction and is substantially removed into the electrostatic series from the material of the filaments, and passing the electrified filaments to a cutting device so as to form a mass of staple fiber, said electrifying surface being moved so as continually to present a different portion for frictional contact with the filaments.

9. Process for the production of staple fibers from continuous filaments of cellulose acetate, which comprises electrifying dry continuous filaments of said material by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction and is substantially removed in the electrostatic series from the material of the filaments, the point of contact between the surface and the filaments being shifted in a direction transverse to the direction of movement of the filaments so as continually to present a different portion for frictional contact with the filaments, and passing the electrified filaments to a cutting device so as to form a mass of staple fiber.

10. Process for the production of staple fibers from continuous filaments of cellulose acetate, which comprises electrifying dry continuous filaments of said material by leading said filaments into contact with a surface of a material that promotes electrification of the filaments by friction, passing the electrified fibers to a cutting device so as to form a mass of staple fiber, leading the fibers from the cutting device by an airstream and combining the fibers while they are air-borne.

11. Apparatus for producing staple fibers from continuous filaments, comprising a surface of a material adapted to contact with and promote electrification of the filaments by friction and a device for cutting the filaments into a mass of staple fiber after electrification.

12. Apparatus for producing staple fibers from continuous filaments, comprising a surface of a material adapted to contact with and promote electrification of the filaments by friction and a device for cutting the filaments into a mass of staple fiber after electrification, said electrifying surface being adapted to move so as continually to present a different portion for frictional contact with the filaments.

13. Apparatus for producing staple fibers from continuous filaments, comprising a surface of a material adapted to contact with and promote electrification of the filaments by friction and a device for cutting the filaments into a mass of staple fiber after electrification, said electrifying surface being adapted to have a relative motion with respect to the filaments in a direction transverse to the direction of movement of the filaments.

14. Apparatus for producing staple fibers from continuous filaments, comprising a surface of a material adapted to contact with and promote electrification of the filaments by friction, a device for cutting the filaments into a mass of staple fiber after electrification, pneumatic means for conveying the staple fiber from the vicinity of the cutting device and means for combing the fibers during their conveyance.

15. Apparatus for producing staple fibers from continuous filaments, comprising a surface of a material adapted to contact with and promote electrification of the filaments by friction, a device for cutting the filaments into a mass of staple fiber after electrification, pneumatic means for conveying the staple fiber from the vicinity of the cutting device, and a delivery pipe fitted with bafiles through which the fibers are conveyed.

16. Apparatus for producing staple fibers from continuous filaments, comprising a surface of a material adapted to contact with and promote electrification of the filaments by friction, a device for cutting the filaments into a mass of staple fiber after electrification, pneumatic means for conveying the staple fiber from the vicinity of the cutting device, and a delivery pipe fitted with toothed bailies through which the fibers are conveyed.

17. Apparatus for producing staple fibers from continuous filaments, comprising a surface of a material adapted to contact with and promote electrification of the filaments by friction, a device for cutting the filaments into a mass of staple fiber after electrification, pneumatic means for conveying the staple fiber from the vicinity of the cutting device, and a delivery pipe fitted with baffies through which the fibers are conveyed, said delivery pipe and said bafiles being con structed of non-conducting material.

CHARLES WESLEY ADDY. REGINALD JOHN. GRINNEIL. 

